The present invention relates generally to the fields of carbon nanotube technology and neurobiology and, more particularly, to a cell and substrate system or nerve regeneration implant and to a method for promoting neuronal growth.
The mammalian nervous system is a complex cellular communication network that contains over 1011 nerve cells or neurons. Each of these neurons has an elaborate morphology including axons and dendrites that extend over long distances. These axons and dendrites are collectively known as neurites. Synapses are the point at which a nervous impulse passes from one neuron to another. The growth of neurites and the formation of synapses during development and regeneration is controlled by highly motile structural specialization at the tip of the neurite called the growth cone. Our ability to develop advances in technology to allow better regeneration and restoring of function of damaged neuronal circuits will first require a heightened understanding of growth cone physiology.
Presently the studying of mechanisms that regulate neurite outgrowth generally employ cultures of disassociated neurons from brains or spinal cords of embryonic rodents. Specifically, the neurons are seeded into dishes having a culture surface that has been coated with a uniform layer of adhesive molecules that promote neurite outgrowth. Although studies using this approach have led to the identification of a number of molecules that promote or inhibit neurite outgrowth, this approach does not allow for the manipulating of the growth environment at the nanometer scale. Accordingly, many mysteries of the growth mechanism remain.
A need is therefore identified for a means of studying neurite outgrowth at the nanometer scale. The present invention relates to a cell and substrate system and a method for promoting neuronal growth which will allow completion of these studies as well as to an implant for effectively promoting nerve regeneration.
In accordance with the purposes of the present invention as described herein, a cell and substrate system or nerve regeneration implant is provided. This system/implant comprises a carbon nanotube and a neuron growing on that carbon nanotube.
The carbon nanotube has a diameter of about 1.0-100.0 nm and a length of between about 20-100 xcexcm. In one embodiment the carbon nanotube is functionalized with a neuronal growth promoting agent. That neuronal growth promoting agent may be selected from a group consisting of 4-hydroxynonenal, acetylcholine, dopamine, GABA (g-aminobutyric acid), glutamate, serotonin, somatostatin, nitrins, semaphorins, roundabout, calcium (Ca2+) mixtures thereof.
In accordance with yet another aspect of the present invention a method is provided for promoting neuronal growth. That method may be broadly described as including the step of growing a neuron on a carbon nanotube.
In accordance with one embodiment of the invention the method may include the step of functionalizing the carbon nanotube with a neuronal growth promoting agent. That agent may be selected from a group consisting of 4-hydroxynonenal, acetylcholine, dopamine, GABA (g-aminobutyric acid), glutamate, serotonin, somatostatin, nitrins, semaphorins, roundabout, calcium (Ca2+) mixtures thereof.
The functionalizing step may include the step of sonicating the carbon nanotubes in an acid solution containing the neuronal growth promoting agent.
The method further includes the step of applying the functionalized carbon nanotube to a glass coverslip. This is followed by the placing of the glass coverslip and attached functionalized carbon nanotube in a culture dish with a culture medium suitable for supporting the growth of neuronal cells. This is followed by the seeding of a neuronal cell into the culture dish.
The benefits and advantages of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described preferred embodiments of this invention, simply by way of illustration of various modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawing and descriptions will be regarded as illustrative in nature and not as restrictive.